The only one with chains confirmed that went cheap was $10,000 after buyer premium, and was a 2010 with 127k on it. And the exterior was beat, and came with 1 key (a $500 problem for those who know). Still a steal, but it wasn't clear that the rear crossover was done since it was a dealer sale, and they flagged it as a "manifold pipe". A 2012 with chains/crossovers/fluids/new tires confirmed was $19k with 95k on the clock. This was three months ago. That vehicle previously sold for $13.6k a year earlier (when the market was hotter), with 20k less miles but with NO chains and NO crossovers done. When it resold, he was smart and had "Timing Chains Replaced" on the auction subtitle. Case closed... Chains and crossovers is a minimum $10000 car. They do not book that high because dealers generally have no idea of service history.
Now, if you go back and look at the "failed engine" thread, nearly all of those failures are indeed cooling related and many of the others, while not always drilling down to the timing chain, sound like timing chain issues. If you take care of those preventatively, and change the oil every 5000 miles with a quality synthetic oil meeting or exceeding original specs, and change the other various fluids, there's no particular reason to expect engine failure. 200k or 250k should be a cakewalk. Unlike certain VW or BMW engines, there aren't a lot of reports of random rod or main bearing failures. This is why I avoided a used Cayenne like the plague. The engines fail "just because" of oil starvation. The AJ133 does not do that.